is it legal to kill shipwrecked people

No, it is not legal to kill shipwrecked people. Under international law, including the law of the sea and human rights law, individuals have the right to life and protection, regardless of their circumstances. Actions that result in the harm or death of individuals, including those who are shipwrecked, would typically be considered murder or manslaughter and are subject to prosecution under national and international law. Additionally, maritime law emphasizes the duty to assist individuals in distress at sea.